About influence of the pulmonary circulation state on the development of thrombocytopenia in pregnant with congenital heart disease

Abstract

Introduction. The large-scale studies on adult patients with congenital heart disease (CHD) demonstrated high prevalence of thrombocytopenia, especially in patients with Eisenmenger syndrome (sEis). The exact reasons for the decline of platelet count in adults with CHD are currently unknown. Objective: to determine the prevalence of thrombocytopenia in a representative group of adult patients with CHD and explore the possible causes of thrombocytopenia. Methods. A retrospective study of 17 pregnant women with CHD was carried out. All women were admitted for delivery to Federal Almazov North-West Medical Research Centre. Data are presented as median (25th, 75th percentile) and as M±σ for parametric variables. Results. The median age was 26 (21; 28) years. The average period of gestation at the time of admission was 31 (28; 34) weeks. 12 (70.6 %) patients had sEis. At the time of admission PAPsys was 88 (82; 98) mm Hg, SpO 2 - 92 (85; 95)%. In whole group the platelet count median was 105 (62; 164) 10 9 /L, while in 12 (71%) women platelet count was less than 150 10 9 /L. There was a significant difference between patients with sEis and women without right-to-left shunt in platelet count: 99 (73; 105) and 162 (138; 166) 10 9 /L, respectively, p<0.001. Mean platelet volume (MPV) in patients with sEis was higher than in women without right-to-left shunt: 12.2±2.4 fl and 10.6±1.6 fl, respectively, p=0.003. Furthermore, a significant negative correlation (r=-0.52) was found between platelet count and MPV. Three patients with sEis died after cesarean section. Thus, the mortality in the entire group was 17.6%, and among women with sEis - 25%. Conclusions. Reduced platelet count is typical for adult patients with sEis. Right-to-left blood shunting with lung bypass and reduced thrombopoiesis in the pulmonary capillary bed are the main causes of thrombocytopenia.